Interior parts for use in automobiles or homes are classified into types of a single-layered molded body made of a resin and types of a molded body having a skin. With respect to the latter, in recent years a foam-molded member having a skin that has a three-layered structure including a skin layer, a foam layer, and a core layer has been used (see Japanese Patent Application Laid-Open Nos. 6-106550 and 11-19938). The foam-molded member having a skin is applied to an automobile interior part, for example, a door trim. To improve the appearance of interior parts directly mounted on an inner panel like the door trim, skin wrapping is performed on the back surfaces of an outer circumferential end portion of a product or a waistline portion connected to, for example, an instrument panel.